The nightgown/bathrobe Arthur Dent wore was the most expensive and difficult of all costumes (including Zaphod’s heads and Humma’s eyes). The fabric had to be sewn on stage and was flown in from Turkey.

According to Douglas Adams’ notes, he wanted the name of the character “Slartibartfast” to sound extremely rude, but still pass BBC’s rules on what could be broadcast – he actually started with “Phartiphukborlz” and changed it, bit by bit, until it was acceptable.

Faint screams can be heard a moment before Mr. Prosser speaks. In the book, Mr. Prosser is a direct male-line descendant of Genghis Khan, the reason why he wears little fur hats and often hears a thousand hairy horsemen shouting in his head.

The relevance of Sector ZZ9 is the fact that in the UK if a person has NFA (No fixed Abode (No place to live)) then the POSTCODE is recorded as ZZ99 3VZ, thus Both Trillian and Arthur come from Sector ZZ9 and thanks to the Vogons they are both of NFA.

The car that Ford Prefect “introduces himself to” is actually a Ford Prefect, from whence Ford got his “Earth name”. Despite being a Ford, the car was never manufactured or sold in the United States, but produced in Ireland, the UK, Malaysia and New Zealand, and sold in Europe, Asia and Australia between 1938 and 1959.